Radiation Quantities and Units

Chapter 3

Sherer

Chapter 33 Bushong

Somatic effects Long term somatic Genetic effects Box 3-1

Quality Factor, pg 56 Sherer "rate in which energy is deposited in the

form of a charged particle or ion pair as it travels through matter"

LET pg 57 Sherer Radiographic isotopes pg 46 Bushong ionization pg. 5 Bushong Natural sources of radiation, pg 5 Bushong

QUALITY FACTOR (QF) measure of biologic impact or damage of a

particular type of radiation Rem = RAD x QF LETS of 3% or less have a QF of 1 = same

amount of damage of rad per rem QUALITY FACTOR OF ALPHA IS 20 See box

Table 3-1 Sherer 1 RAD = 20 REM FOR ALPHA PARTICLE

ABSORPTION

WHICH HAS A HIGHER LET NUMBER?

X-rays (HIGH OR LOW?) Alpha (HIGH OR LOW?) Beta (HIGH OR LOW?) Gamma (HIGH OR LOW?)

Radiation Induced Responses

NON-STOCHASTIC AKA (DETERMINISTIC)

STOCHASTIC AKA PROBABILISTIC

What do they mean?

Exposure (X) Absorbed dose (D)

Equivalent dose (EqD)

Effective dose (EfD)

What strikes the body Deposit of energy in body

Calculated based on absorbed dose and associated radiation weighting factor (type/energy of a specific radiation)

More tissues radiosensitive than others (tissue weighting factor see Table 3-3

WR associated with Equivalent Dose- table 3-2

WT associated with Effective Dose- table 3-3

Radiobiology and Cellular Biology (Bushong Chapter 33)

When an atom is ionized

Chemical binding properties change in large molecules: breakage or relocation

of molecules…become abnormal Abnormal means Function improperly cease to function -impairment or death of

cell

Damage is Reversible

Ionized atoms become neutral…How? Molecules are mended by repair enzymes Immediate response to radiation Latent response Pg 484 (Bushong) see Box 33-1

RADIATION INTERACTS AT ATOMIC LEVEL Atoms combine to form molecules The body is made of macromolecules What is the definition of macromolecules?

With this kind of potential damage….

The government tends to get involved

CHAPTER 7 SHERER

YOU ARE RESPONSIBLE FOR DIFFERENTIATING BETWEEN ICRP NCRP UNSCEAR NAS/NRC-BEIR NRC EPA FDA OSHA

DEFINE

RSC

RSO

NCRP REPORT NO 116